[Asterisk-bsd] Polarity reversed (0 -> 1)

[Graham S. Jarvis]

Hello all,

Does anyone know what "Polarity reversed (0 -> 1)" means?
Here's a section of the output:


Zapata Telephony Interface Registered on major 196
.
.
wcfxs0: <Wildcard TDM400P REV E/F> port . . .
.
.
Module 0: Installed -- AUTO FXS
.
Module 1: Not installed
.
Module 2: Not installed
.
Module 3: Installed -- AUTO FXO
Found a Wildcard TDM: Wildcard TDM400P REV E/F (4 modules)
.
.
.
Polarity reversed (0 -> 1)


I can dial out but incoming calls are not answered.

I found a tread at:
http://lists.digium.com/pipermail/asterisk-bsd/2005-February/000571.html
But I'd like to know what "AUDIO_RINGCHECK" has to do with "Polarity
reversed" before I simply comment it out.
On the face of it they have nothing to do with each other.

Can someone give me a quick idea on what's going on here?

Thanks in advance,

-Graham-